Alto de la Virgen

Overview

Alto de la Virgen is a hors catégorie (HC) climb, the hardest rating there is before you run out of categories. It stretches 39.9 km from a start elevation of 774 m to a summit at 2730 m. That is a net elevation gain of 1956 m, and because the road undulates rather than climbing in a single clean line, the total ascent adds up to 2162 m — you gain and give back a little along the way. The average gradient sits at 4.9%, but that headline figure hides a spike of 15.31% waiting somewhere in the profile. This is an endurance climb first and a punchy climb second: nearly 40 kilometres of near-continuous uphill is a test of patience long before it becomes a test of power.

How the Gradient Unfolds

A 4.9% average across 39.9 km sounds gentle, and in places it is. But the 15.31% max tells you the road is not uniform. Expect long stretches close to the average that let you settle into a rhythm, broken by sharper ramps that force you out of the saddle or down a couple of gears. The gap between 4.9% and 15.31% is the whole story here — the climb rewards riders who can absorb the steep bites without blowing their composure, then return to steady tempo once the gradient relaxes. With 2162 m of total ascent against 1956 m of net gain, there are also brief flatter or descending sections; use them to recover, not to attack.

Pacing Notes

On a climb this long, pacing is everything. Ride the first two-thirds well within yourself — the 15.31% ramp and the thin air near 2730 m will punish anyone who spends too early. Anchor your effort to your FTP: on the sustained 4.9% sections aim to sit comfortably below threshold, saving your matches for the steep pitches where you have no choice but to push over it briefly. If you do not know your current threshold, run the numbers through the FTP estimator before you go, then translate that into a realistic power ceiling for a 39.9 km effort. Fuel and drink steadily from the bottom; on a climb gaining 1956 m, the mistakes you make in the first hour show up in the last kilometres.

Gearing

Gear for the steep ramp, not the average. A 15.31% pitch after tens of kilometres of climbing is where undergeared riders grind to a walking pace. A compact 34-tooth chainring paired with a 34×32 cassette is the sensible baseline for most riders here. If you climb at a lower cadence, run heavier, or simply want insurance for the 2730 m altitude sapping your legs, size up to a 34×34. The extra sprocket costs nothing on the shallow sections and buys you a spinnable gear when the road kicks up.

Summary

Alto de la Virgen is a long, patient HC climb defined by its scale rather than any single wall: 39.9 km of climbing, 1956 m of net elevation gained, and a summit at 2730 m in the thin mountain air. Ride it steady, gear it generously, and respect the 15.31% ramp hiding inside a 4.9% average.

Length: 39.9 km
Average gradient: 4.9%
Max gradient: 15.31%
Start: 774 m
Summit: 2730 m
Net gain: 1956 m
Total ascent: 2162 m
Category: HC